A video that went viral on Thursday of Siberian tigers chasing a drone may have a dark side, various media outlets have pointed out.

In the video, published by China Central Television, a state-run channel, a group of tigers run after a drone and eventually knock it out of the sky. The drone was reportedly part of the tigers’ keepers’ plans to keep the animals fit.

But the video’s fun value didn’t last long. A translated of the original caption accompanying the video revealed that the tigers live at Harbin Siberian Tiger Park, a facility in northeast China where tigers are allegedly slaughtered for the commercial trade. The country has only an estimated seven tigers in the wild, in northeastern China, and the animals in the video are clearly obese—a sign of overfeeding.

Ben Pearson, from World Animal Protection, an animal welfare group based in England, told ABC News that the park had been transformed from a tiger farm to a tourist park in the 1990s following a national ban on the domestic trade of tiger bones.

A 2014 McClatchy investigation revealed that many of the park’s tigers are kept in small cages, where they roll in their excrement. The article, citing investigators from the Environmental Investigation Agency, an organization that tackles the illegal wildlife trade, said that the park’s true profit doesn’t come from tourists but rather sales of tiger pelts, tiger bone wine, and other products banned in China.

There are many such facilities in China—and across Asia.

What is a tiger farm?

A tiger farm is a facility that breeds tigers like livestock. While alive, the tigers attract tourists who come to gawk at the animals and even take selfies. Cubs in particular are a draw, encouraging speed breeding in which cubs are taken away from their mothers at a young age, forcing the females to go into heat again sooner than they would in nature. Tigers are later slaughtered for the luxury and medicinal markets. Farms range from small operations to industrial-size facilities, like those in China. They may be promoted as zoos or sanctuaries, such as Thailand’s infamous Tiger Temple, a popular tourist destination that was raided by authorities last year on the suspicion of tiger trafficking.

Why do people want tiger parts?

Live tigers may be bought and sold to other tiger farms, where they’re used as props for tourists and as breeding stock, but most of the demand is for luxury goods and traditional medicine.

Some believe, erroneously, that tiger bone wine, which is made by steeping the animal’s bones in rice wine, will impart the drinker with the animal’s strength. Sellers have found many ways to get around China’s tiger wine ban, including simply taking the word “tiger” off the label. Bones are also ground into a powder and turned into pills, often sold as a cure for rheumatism. And tiger penis is said to be an aphrodisiac.

Tiger parts are also used as a status symbol. Tiger rugs and necklaces with amulets containing pieces of tiger skin show off an owner’s wealth and prestige. Tiger claws and teeth are bought as charms, and meat is sometimes on the menu as a delicacy.

How many tigers are in captivity and where?

China alone has an estimated 5,000 to 6,000 captive tigers. In total there are believed to be 7,000 to 8,000 tigers on farms in Asia and Southeast Asia, compared to no more than 4,000 left in the wild (and that may be an overly generous estimate). There are also several tiger farms in South Africa. An estimated 5,000 to 10,000 tigers live in captivity in the United States, in backyards, roadside zoos, and private menageries, and there are more tigers in captivity in other parts of the world

In 2007 the international community passed a decision at a meeting of the Convention on International Trade on Endangered Species of Wild Fauna and Flora (CITES) agreeing that tigers should not be bred for trade in their body parts and saying that tiger farms should be scaled back. Numerous reports have subsequently shown, however, that both the domestic and international trade in tiger parts has grown.

Do tiger farms help protect wild tigers?

Proponents of tiger farms say they take pressure off wild populations. Most conservationists agree that tiger farms simply increase the demand for tiger products.

“If there was any indication that they led to tigers in the wild not being persecuted, we would have seen it by now. We haven’t,” Kanitha Krishnasamy of TRAFFIC, the organization that monitors wildlife trade, told National Geographic in October.

Tiger farms help erase the stigma around tiger products, encouraging more people to buy them, and it’s believed that they fuel poaching of wild tigers. Some consumers believe wild tiger “medicines” are more potent than those from captive-bred tigers.

“Trade in parts and derivatives of captive-bred tigers perpetuates the desirability of tiger products, in turn stimulating poaching of wild tigers,” Debbie Banks, of the Environmental Investigation Agency, a London-based NGO, told National Geographic in October.